Non 3D printed parts

Buy needed accessories in advance to save time

General advice is to order most of all main accessories as soon as posible. At least accessories listed on this page. While you print Amethyst parts and there will be lot of printing, accessories will be on the way to your post box. Please check out our components list for complete overview.



Non printed parts


Amethyst is designed to use one of the cheapest brushless motor on the market. It is convenien for beginners, great for experimenting and clever when such a harch environment they will be used in is taken in to account - in simple words, they are more easily expendable.

This Chinese motor is more or less copy of TUNINGY original. It has simplier upper vent holes and is without screw holes on upper side as well. It cost 4 - 6 EUR, which is as fare as I know the absolute cheepest motor on the market today. For our needs this motor is just perfect.

Amethyst AUV Brushless motor

Buy at least 3 pieces, 5 is recomended. Motors are really cheap, so if you take even more of them as spare, it will not drain your bank account. Chose those with low KV characteristic. This motor is must due to exact dimensions bound to design of Amethyst sections and propellers.

Check the buers list to find supplier.



Non printed parts


Servo motor is used to controll stearing and correct depth of the craft by rotating of the rudder fins. Amethyst use cheap ordinary micro servo you could find on Amazon, Aliexpress or elsewhere. They are really common.

Amethyst AUV Servo

Buy at least 3 of them. To get more as spare is good idea. This servo is must due to exact dimensions bound to design of Amethyst stearing mounts. 

Check the buers list to find supplier.



Non printed parts


This batteries are bigger (and then with bigger capacity) version of clasic "notebook" 3.7 V Li-ion battery. They are also heavier wich is good for buoyancy balancing. Keep in mind that you will need charger for them as well - to be more specific, you will need two chargers to charge 2x3 batteries at same time. Check our buy list and find suitable chargers if you are bit new to this stuff. 

Amethyst AUV 26650 Li-ion Batteries

Buy at least 6 pieces of 26650 3.7V batteries with capacity you find and your charger is able to charge. Watch out, some chargers can´t charge cells above 5000 mAh. Buy 12 if you want to fast swap batteries or battery packs on extended dives at remote (without access to electricity) places. 26650 type battery is must due to exact dimensions bound to design of Amethyst battery packs.

Check the buers list to find supplier.



Non printed parts


Tube is essential part of Amethyst concept used to accomodate craft´s electronic in dry compartment. Its convenien, cheap and visual for development of craft´s electronic systems. Offcourse its possible to print this part with printer, but you must do it with superior print quality and properly coate this print for maximum water tight characteristic. You can use internet search to sure find local supplier of acrylic goods.

Amethyst AUV Acrylic Tube

One 290x90x(84inner) mm  tube is enought, but some suppliers do not sell piece shorter than 1 meter. Ask your supplier to cut that 1 meter in to 5 pieces then. If its not possible, go and find another one.



Non printed parts

Sealing O-Rings

This o-rings are needed to seal our dry compartment.

Amethyst AUV O-rings

Buy at least 2 of 85x2 mm o-rings. Vendors selling fasteners or pulleys should have them in their catalogue.



Non printed parts

Screws and bolts

How manyTypeType note
102x M3x10 Stainless steel hex socket head cap screw
8x M3x12 Stainless steel hex socket head cap screw
16x M3x16 Stainless steel hex socket head cap screw
8x M3x25 Stainless steel hex socket head cap screw
3x M3x30 Stainless steel hex socket head cap screw
16x M3x40 Stainless steel hex socket head cap screw
142x M3 bolt Stainless steel
280x M3 washer Stainless steel washer for cylindrical head screw M3
12x M3 spring washer Stainless steel spring washer for M3 screw



Non printed parts

2-line and 3-line wires

You will need 2 line wire for external battery pack completion and for external sensors / anthenas / switches. 3 line wires are mainly for motors and servos. 2 meters of each type will be more than enought.


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